Oil filter



Apri|13,1937- R: N. BURCKHALTER 2,076,935 1 OIL FILTER Filed Aug. 3, 1934 3 Sheets-Sheet 1 '45 49 Q7 52 3Q 46 31 i 43 I W 3 51 H 32 33 J6 52 a I J 66 I i 67 0 4 i y 69 g 27 i l i: l b

April 13, 1937. BQURCKHALTER 2,076,935

I OIL FILTER Filed Aug. 3, 1954 5 Sheets-Sheet 2 April 13, 1937.

R. N. BURCKHALTER 2,076,935

011. FILTER Filed Aug. 3, 1934 3 Sheets-Sheet 3 Patented Apr. 13, 1937 2,076,935 011. FILTER Robert Nash Burckhalter, Michigan City, Ind., assignor to Michiana Products Corporation, Michigan City, Ind., a corporation of Indiana Application August 3, 1934, Serial No. 738,306

15 Claims. (Cl. 210-131) The principal object of this invention is to provide a small filter that will thoroughly cleanse the large quantities of oil required for improved automotive engines and endure a long period of service.

Generally speaking, this is achieved by using a plurality of filter elements of high permeability to lubricating oil; one a loose fibrous mass readily admitting to and retaining within its interior the impalpable solids, like colloidal carbon; and another of extremely fine 'wire cloth enclosing the first, and straining out of the oil all the solids injurious to bearings.

Further objects and advantages will be appa l5 ent from the description taken in connection with the drawings, in which Fig. 1 is a vertical section through one form of filter for removing all solid matter and acids from lubricating oil of an automotive engine;

Fig, 2 is an enlargement of a fragment of Fig. 1 to better show some of the details;

Figs. 3 and 4 are sectional views taken on the lines 33 and 4-4 of Fig. 1;

Fig. 5 is an enlargedsection through wire cloth 25 used in making one of the filter elements;

Fig- 6 isa view normal to the surface of such cloth;

Figs. 7, 8 and 9 are transverse sections taken on the line '|'l, 8-8 and 99 of Fig. 6;

Fig. 10 is a plan of a blank used in making a barrel filter element of wire cloth;

Fig. 11 is a diagrammatic end view illustrating how the blank is wound on a mandrel as a pre: liminary to soldering;

35 Fig. 12 is a side elevation corresponding to Fig. 1, in miniature, with parts displaced to illustrate how they may be assembled and taken apart;

Fig. 13 is an enlarged fragment of a sheet 40 metal disk, or head, used in making one of the filter elements;

Fig. 14 is a transverse section through a sheet metal tube used in making one of the filter elements,

Fig. 15 is a vertical section through another embodiment of one phase of the invention.

The filter shown on sheet 1 (Figs. l, 2, .3 and 4) .includes a base casting having a fiat machined face Ill (Figs. 3 and 4) adapted to fit against a 50 pad on an engine casing, or the like, when the filter is mounted thereon by bolts passing through holes II in the flange l2.

The base affords a generous oil chamber ii] that may be drained below by removing a plug I4, 55 and there are two pipes I5, I6, extending upwardly and fitted with cap nuts II, I8, for securing drawn shells l9 and 20, with their lower edges received in grooves 2| and 22 on the upper face of the base.

Oil from the pump enters a cored pocket 23 (Fig. 3) connected by a bore 24' with the bypass chamber 25 of a pump limiting valve 26 which, in turn, is connected by a. bore 21 with another cored pocket, by which the oil is returned to a supply reservoir.

The inlet pocket 23 is also connected by an angular bore 28 with an inlet delivery pipe 29 leading to the filter chamber within the shell 20.

The solids of a size sufiicient to injure the bearings are strained out by a barrel filter element comprising a cylinder 30 of fine wire cloth having its ends clamped between flanges 3| and 32 of sheet metal heads 33 and 34. The wire cloth is so fine as to require support against inlet pressure, which is here afforded by a coil 35 of No. 9 steel wire and a cylinder of six-mesh calendered wire screen 36.

The colloidal carbon and other solids not injurious to bearings, but discoloring the lubricating oil, are removed by, fibrous filter elements 31, confined byconcentric cylinders or tubes 38 and 39, and perforated heads 40, M, 42 and 43, the heads to and 43 being made fast by spinning over the ends of the tube 38, as indicated at 44, and the 7 whole becoming a sort of filter cartridge.

The upper sheet metal head 34 is cut away, as indicated at 45, to permit this cartridge to be inserted into or removed from the outer barrel filter element. The closure is made by a flanged head disk 46 resting against gaskets 4i and 48 and made fast by a nut 49 on the threaded upper end ofthe tube H5.

The inner tube 39 of the filter cartridge has its ends turned inwardly to form flanges 50,, one of which supports the gasket 48 and the other rests upon a gasket 5!, bearing against the lower sheet metal head 33, and this, in turn, is supported by a spacer tube 52 resting on a lock nut 53.

The pressure diflferential on the barrel '30 should be kept low, and this may be done with a bypass by making the disk 46 include a tube 54, threaded to receive a valve seat ring 55. cooperating with a ball valve56, urged by a spring 51, compressed against a bridge piece 58.

The intermediate heads 4| and 42 rest against a hollow' spud 59 soldered in a hole 60 in the cylinder 38 and threaded to receive a valve ring 6| cooperating with a ball- 62, urged to a seat by a spring 63 bearing against the tube 39. Holes 64 in the spud communicate with the chamber 65 between the heads 4i and 42, and holes 86 in the tube 39 establish communication with holes Win the tube It, by which oil is lead to the upright bore 88 in the base from which it escapes laterally at 89 to the bearings, if the filter is connected in series, and to the reservoirif in shunt. The bypasses relieve the system when the oil is cold.

The wire cloth from which the barrel 30 is made comprises 208 vertical wires per inch, each about five-thousandths of an inch in diameter and interwoven with sixteen horizontal wires Der inch about seven-thousandths of an inch in diameter. Both Monel metal and phosphor bronze have been found satisfactory in use, and of course other metals may be used.

In making this filter element, a rectangular blank 10 (Fig. 10) is cut from a sheet and the corners II are beveled. The edges 12, I3, 14, are dipped first in flux and then in molten solder, the blank is rolled about a mandrel I5 and the edges 13 and It brought into overlapping relation on an aluminum strip 11, after which they are soldered by applying heat and pressure, as by running the heavy soldering iron along the overlapping edges.

The ends of the barrel thus formed are sealed with the two sheet metal heads 38 and 34 by bending the marginal portion, as best shown in Fig. 2, to grip what was formerly the edge portions 12 and H. The solder that was picked up on these edge portions forms beads 18 about which the sheet metal is rolled or spun.

The filter elements 31 are preferably made of 0 shredded cotton, uniformly distributed and only .compacted enough to give a slight resiliency when the head 43 or 44 is pressed inwardly. Of course other fibrous materials such as wool, hair, asbestos and mixtures of cotton and cattle hair, cotton and wool, wool or cotton and steel wool, may be used, as preference dictates. This element is to readily admit the oil with the entrained colloidal solids, retaining the latter and allowing the oil to pass through.

In operation the oil enters through the tube 29 and fills the chamber enclosed by the shell 20. It filters through the wire cloth, then through the heads 40 and 43, then through the fibrous material 31, and then out through the tubes 39 and I6.

The solid matter of suilicient' size to inJure the bearings, together with tar and the like, collects against the wires forming a sort of filter element that increases the ability of the screen to stop such material. The pressure differential on the screen should be kept as low as possible for best results, both in filtering and in shedding the collecting material when the inlet pressure is .relieved or removed. The barrel screen shown presents about seventy (70) square inches and works well at a pressure differential of three and one-half (3 pounds per square inch, although less pressure enhances the results.

As the screen becomes heavily coated naturally the pressure will tend to distort it from the barrel shape and upon relieving a tendency to recover will assist in shedding the accumulation.

The horizontal warp wires 19 are practically straight while the vertical woof wires are bent in and out to pass between each two adiacent horizontal wires and each vertical wire crosses and contacts each of the two vertical wires next to it. Figs. 5 to 9 are an attempt to show the relation on a large scale. a

208 wires five-thousandths of an inch in diameter would actually present a combined width of one and forty-thousandths (1 and 40/ 1000") inches when laid parallel and in contact, but in the fabric described they are compacted within an inch of horizontal width, the forty-thousandths of an inch excess being absorbed at the intersections where they contact, which is theoretically a point.

As a result, the vertical wires present a complete wall to fiow normal to the filter surface or radial to the barrel. The passages through the fabric are indirect and irregular, somewhat triangular in shape.

An attempt to explain the operation of this cloth as a filter might result in error or controversy. Many filters having this shape, and seven and one-sixteenths inches (7 long and three inches (3") in diameter, have given excellent service in four and six cylinder truck engines.

The wire cloth will remove from the oil all solid matter injurious to bearings and will continue in operation indefinitely. The fiber elements will strain out the colloidal solids and preserve the color of the oil for a long period of service until the accumulation of fine solid matter so charges the fiber that some of it begins to escape with the oil, then the filter cartridge should be replaced by a new one. I This is a simple operation, roughly illustrated in Fig. 12, where it will be seen that by removing the cap l8, the shell 20 may be taken off and by then removing the nut 49, both the filter elements may be slipped on the tube l8, when the inner cartridge may be readily withdrawn through the opening 45 in the head 44, and replaced by a new one. Putting the bypass in the middle of the cartridge has the advantage that it may be inserted either end first. Wire cloth of other weaves may,of course, be used, but those presenting elongated, triangular openings will be found most suitable for engine oil.

In some instances oil contains an appreciable quantity of acid injurious to the metal parts. For use in such cases the filter, above described, may

be supplemented with a filter element 8| compassage. 68 to the chamber enclosed by the shell l9 and also with an outlet discharge port 81.

The tube i5 is perforated at 88 above the head passage 86 leading to a This construction places the fullers earth filter element in a sort of shunt circuit subject to the outlet pressure of the other filter system. Oil enters through the passage 85, rises through the fullers earth, passes through the opening 88, thence down through the tube I 5 and out through the passage 88.

Fig. 15 illustrates a much simplified form of filter based on a construction similar to that of the filter cartridge described in connection with Fig. 1. A base indicated at 89 has an inlet 90 and an outlet 9|, a perforated tube 92 is threaded into the base and communicats with the outlet, a nut 93 threaded on top of the tube serves to fasten a shell 94, fitted in a groove I04, on top of the base. A filter cartridge includes a central tube, or sleeve 95, an outer barrel or sleeve 90, and. four perforated heads 91, 98, 99 and I00, the heads 91 and I being made fast by spinning over the ends of the barrel 96 to form flanges IN.

The intermediate portion of the tube 95 has ribs l02 (Figs. 14 and 15) sixty degrees apart and cooperating with recesses I03 (Fig. 3) in the heads 98 and 99.

The tube 95 has its opposite ends spread to form conical flanges I05, which cooperate with cork washers I06, preferably rectangular in section, so that when compressed to the shape shown a tight seal is made.

In operation the oil enters theinlet, rises into the shell 94, passes through the perforations in the heads 91 and E00, permeates the confined filter material I01, (which is the same as described'in Fig. 1) to an intermediate chamber I08, and escapes through holes I09, H0, into the tube 92 to the outlet 9|.

Providing two filter elements, I01, Fig. 15, and. 31 in Fig. 1, the speed of flow is cut in half, which, in effect, doubles the capacity of the filter. The pressure on the fibrous material I0! is about right when the heads 91 and I00 will show slight resiliency under endwise pressure.

These fibrous filter elements are so loose as to permit the oil to flow freely, and permit the solid matter to penetrate to a considerable depth. In fact, the colloidal carbon, and other impalpable powdered matter will, in time, work through the fibrous filter element.

The form shown in Fig. 15, is intended for use where the filter element can be replaced at comparatively short intervals, say 7000 or 8000 miles, and the work is light.

The form shown in Fig. 1 is intended for use where the fibrous filter element will be replaced less frequently and then by the hands of skillful operators who can clean the wire cloth and restore it to its original condition.

The form shown in Fig. 1 is intended for use with heavy duty engines-buses, trucks, tractors, and the like-where the engines develop eighty (80%) percent of their horse power most of the time.

The barrel filter element and the fibrous cartridge elements are highly permeable to warm or hot engine oil and permit the rapid flow necessary to pass the required quantity of oil. The wire cloth protects the fibrous material from the large solid matter, tar, and the like, that would reduce its useful life. The fine material that passes through the wire cloth will in time work through the fibrous cartridge, which occurrence marks the need for replacement.

However, no damage to the bearings results from failure to replace the fibrous cartridge for -the solids that get through it have no abrasive effect on the lubricated surfaces, but merely discolor the oil.

Even when assembled under sufficient pressure to give the fibrous cartridge a small amount of resiliency before it is put into use, the fibrous elements will shrink lengthwise to the shell and thus reduce the thickness through which 011 must pass. Allowance for this should be made to the end that the thickness after shrinkage will be appro- .priate to the filtering'required.

The wire cloth barrel may be assisted by collected solids, etc., forming a sort of filter bed during each period of operation, but the majority of this collected material is shed when the operation is stopped.

The pressure differential should be kept low enough to avoid forcing this extraneous matter between the wires that bound the openings in the wire cloth. Most of the filters embodying this invention now in service are operated at three and one-half pounds, or less, per square inch pressure differential between opposite sides of the filter cloth. However, in some heavy duty applications six pounds per square inch is used.

The shedding of the collected material is probably due to the fact that the wire cloth bends inwardly about the wires of the six mesh screen 36, while in operation, and tend to straightenwhen the operation ends. The head 33, to which the lower end of the barrel is fastened, is sufficiently resilient to foster that sort of movement.

The wire cloth here described is the form preferred, but other weaves can be used and obviously the cylindrical barrel shape. is not essential, though also preferred.

The assembly on the tube 95 (Fig. 15) forms a cartridge that can be readily inserted and removed. It may be used in new filters and also to form a replacement unit for many filters now in service having different forms of filtering elements.

I claim as my invention 1. In a filter, a barrel screen of flexible material, means for directing the flow of oil through the screen inwardly, a grating sustaining the screen against inlet pressure, a removable cartridge within the grating comprising loose fibrous material, means for bypassing oil around the screen, and other means for bypassing oil around the cartridge.

2. In a filter, a perforated tube, heads secured to the tube on opposite sides of the perforation, a barrel screen extending between the heads, having passages great enough in total to pass liquid rapidly and small enough individually to exclude solid matter that would injure bearings, and a filter element within the barrel and removable therefrom including a casing having inlet and outlet openings and charged with loose fibrous material of considerable thickness.

3. In an engine lubricating oil filter, an outer filter element comprising a barrel screen excluding substantially all solids injurious to bearings, an inner filter element comprising imperfo'rate concentric shells containing a loose permeable mass of fibrous material to retain colloidal solids, and ducts for conducting oil to be filtered first to the outer element and thence longitudinally through the inner.

4. In an engine lubricating oil filter, an outer filter element comprising a barrel screen excluding substantially all solids injurious to bearings, an inner filter element comprising imperforate spaced shells connected at their ends by perforate heads and containing a loose permeable mass of fibrous material to retain colloidal solids, and ducts for conducting oil to be filtered first to the outer element and thence to one of the heads for passage therethrough, through the fibrous material, and through the other head.

5. In an engine lubricating oil filter, an outer filter element comprising a barrel screen excluding substantially all solids injurious to bearings, an inner filter element spaced inwardly from said outer element and comprising spaced, imperiorate, concentric shells containing in the space between them a loose permeable mass of fibrous material to retain colloidal solids. ducts for conducting oil to be filtered first to the outer element, thence intothe space between the outer and inner elements and thence longitudinally through the inner, and asump for receiving solids excluded by the outer filter element.

6. In a pressure filter for engine lubricating oil, a casing providing a chamber adapted to'receive contaminated oil under pressure, a barrel screen outer filter element in the casing having closed end heads and adapted to exclude substantially all solids injurious to bearings, an inner filter element separated from the screen 01' the outer filter element by an open space and comprising imperiorate side walls and perforate end heads enclosing a loose permeable mass of fibrous material adapted to retain colloidal solids, and means conducting oil from said chamber radially through the outer filter element and from the inner filter element to the exterior of the casing.

7. In a pressure filter for engine lubricating.

oil, a casing providing a chamber adapted to receive contaminated oil under pressure, a barrel screen outer filter element 'having closed end heads and adapted to exclude substantially all solids injurious to bearings, means supporting said screen inthe chamber against inlet pressure, said means permitting the screen material to fiex for shedding retained solids, a sump for receiving said solids, an inner filter element separated from the screen of the outer filter element by an open space and comprising a loose permeable mass of fibrous material adapted to retain -colloidal solids. and means conducting ,oil from saidchamber radially through the outer filter element, thence through said open space, thence through the inner filter element, and from the inner element to the exterior of the casing. a

8. In a filter for engine lubricating oil, an outer filter element comprising screen adapted to exclude substantially all solids injurious to bearings, means supporting said screen against oil pressure, said means permitting the screen material to fiex for shedding retained solids, and an inner filter element positioned to receive oil which has passed through the outer element, said inner element comprising concentric imperforate cylinders and perforate end heads containing a loose permeable mass of fibrous material-adapted to retain colloidal solids.

9. In a filter for engine lubricating oil, a casing,'an outer filter element comprising a barrel screen adapted to exclude substantially all solids injurious to bearings, means supporting said screen in the casing against oil pressure, said means being yieldable to permit the screen material to flex for shedding retained solids into a lower part of the casing, and an inner filter element positioned within the barrel screen and comprising concentric imperforate shells and periorate end heads'containing a filter body adapted toretain colloidal solids passed by the barrel screen. ,7;

10. In a filter, a barrel-screen having imperforate end heads, a pair of filter cartridges within the barrel screen, spaced therefrom and from each other to provide a central space, a bypass for the barrel screen comprising a valve in one of the end heads adapted to establish communication between theoutside of the barrel screen and the space between said screen and the filter cartridges, and a bypass for the filter cartridges comprising a valve foradmitting fiuid from the last named space into the central space.

aomcss 11. In a. filter, a barrel screen having end heads, concentric cylinders within the barrel screen spaced therefrom and from each other, end heads and intermediate heads dividing the space between the cylinders into chambers separated by an intermediate space, filter bodies in said chambers, a bypass for the barrel screen comprising a valve in one of the barrel screen end heads adapted to establish communication between the outside of the barrel screen and the space between said screen and chambers, and a bypass for the filter bodies comprising a valve in the outer cylinder for admitting fluid from the last named space into the intermediate space.

12. In a filter for internal combustion engine lubricating oil contaminated with impurities including solids injurious to bearings and impalpable solids such as colloidal carbon which discolor the oil, a pair of filter elements comprising wire cloth having a mesh excluding substantially all of the first named impurities and passing substantially all of the second named and a cylindrical body comprising a loose permeable mass of fibrous material retaining the second named impurities, and ducts for conducting oil under pressure in series through the wire cloth filter and thence lengthwise through the fibrous filter.

13. In a filter for internal combustion engine lubricating oil contaminated with impurities including solids injurious to pable solids such as colloidal carbon which discolor the oil, a pair of filter elements comprising wire cloth having a mesh excluding substantially all of the first named impurities and passing substantially all of the second named and a cylindrical body comprising a loose permeable mass of fibrous material retaining the second named impurities, means mounting the two filter elements and providing an open space between them, and ducts for conducting oil under pressure in series through the wire cloth filter, through the space between them, and thence longitudinally through the fibrous filter.

14. In a filter for internal combustion engine lubricating oil contaminated with impurities including solids injurious to bearings and impalpable solids such as colloidal carbon which discolor the oil, a pair of .filter elements comprising wire cloth of approximately the order'oi two color the oil, a pair of filter-elements comprising wire cloth of approximatelythe order of two hundred meshes per inch excluding substantially all of the first named impurities and passing substantially all of the second named and a loose permeable mass of fibrous material retaining the second named impurities, means mounting the two filter elements and providing an open space between them, and ducts for conducting oil in series through the wire cloth filter and thence through the fibrous filter and separate bypass valve means for each filter.

ROBERT NASH BURCKHALTER. 

